CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017
Cash flows from operating activities:
Net loss	$ (24,365)	$ (71,110)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization of intangibles	6,281	6,232
Depreciation	9,910	11,045
Stock-based compensation	14,202	11,107
Amortization of discount on convertible debt and issuance cost	4,482	4,060
Restructuring, asset impairment and loss on retirement of fixed assets	1,105	565
Amortization of non-cash warrant	1,185	38
Deferred income taxes, net	1,056	0
Foreign currency adjustments	(1,034)	1,795
Provision for excess and obsolete inventories	1,259	5,578
Allowance for doubtful accounts and returns	1,357	4,309
Other non-cash adjustments, net	286	298
Changes in operating assets and liabilities:
Accounts receivable	(9,585)	11,367
Inventories	997	6,188
Prepaid expenses and other assets	2,507	6,702
Accounts payable	(4,032)	2,129
Deferred revenue	1,783	(1,098)
Income taxes payable	461	(2,122)
Accrued and other liabilities	(2,188)	(3,053)
Net cash provided by (used in) operating activities	5,667	(5,970)
Cash flows from investing activities:
Proceeds from maturities of investments	0	3,106
Proceeds from sales of investments	104	3,792
Purchases of property and equipment	(4,703)	(9,075)
Net cash used in investing activities	(4,599)	(2,177)
Cash flows from financing activities:
Proceeds from other debts and capital leases	5,066	6,344
Repayment of other debts and capital leases	(6,568)	(7,008)
Proceeds from common stock issued to employees	4,299	4,697
Payment of tax withholding obligations related to net share settlements of restricted stock units	(166)	(2,757)
Net cash provided by financing activities	2,631	1,276
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(580)	1,471
Net increase (decrease) in cash, cash equivalents and restricted cash	3,119	(5,400)
Cash, cash equivalents and restricted cash at beginning of period	58,757	57,420
Cash, cash equivalents and restricted cash at end of period	61,876	52,020
Reconciliation of cash, cash equivalents, and restricted cash to the condensed consolidated balance sheets
Total cash, cash equivalents and restricted cash	$ 58,757	$ 57,420